Shrinking Nemo – global warming to make fish smaller

Changes in ocean and climate systems could lead to smaller fish, according to a new study led by fisheries scientists at the University of British Columbia.

The study, published today in the journal Nature Climate Change, provides the first-ever global projection of the potential reduction in the maximum size of fish in a warmer and less-oxygenated ocean.

The researchers used computer modeling to study more than 600 species of fish from oceans around the world and found that the maximum body weight they can reach could decline by 14-20 per cent between years 2000 and 2050, with the tropics being one of the most impacted regions.

“We were surprised to see such a large decrease in fish size,” says the study’s lead author William Cheung, an assistant professor at the UBC Fisheries Centre. “Marine fish are generally known to respond to climate change through changing distribution and seasonality. But the unexpectedly big effect that climate change could have on body size suggests that we may be missing a big piece of the puzzle of understanding climate change effects in the ocean.”

This is the first global-scale application of the idea that fish growth is limited by oxygen supply, which was pioneered more than 30 years ago by Daniel Pauly, principal investigator with UBC’s Sea Around Us Project and the study’s co-author.

“It’s a constant challenge for fish to get enough oxygen from water to grow, and the situation gets worse as fish get bigger,” explains Pauly. “A warmer and less-oxygenated ocean, as predicted under climate change, would make it more difficult for bigger fish to get enough oxygen, which means they will stop growing sooner.”

This study highlights the need to curb greenhouse gas emissions and develop strategies to monitor and adapt to changes that we are already seeing, or we risk disruption of fisheries, food security and the way ocean ecosystems work.

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Note the press release headline: Fish getting smaller as the oceans warm: UBC research – they tout that as if it were measured, it isn’t.

Of course actual field experiments with real data trump models every day of the week and twice on Sunday. For example here’s a graph from the paper The effect of temperature and fish size on growth, feed intake, food conversionefficiency and stomach evacuation rate of Atlantic salmon post-smolts by Handeland et al published in the journal Aquaculture in June 2008:

Fig. 1. Mean weight in Atlantic salmon smolts (±SE, n=23) transferred to seawater at 6 (□), 10 (Δ), 14 (⋄) and 18 (○) °C. The first point (week 0) refers to the freshwater group (control). Different letters indicates significant differences (Student–Newman–Keuls, pb0.05) between temperature groups at same time of sampling, n.s., non significant.

The authors conclude:

In conclusion, the present study shows ontogenetic variation in optimum temperature for growth in juvenile Atlantic salmon smolts, with increased temperature optimum for growth and decreased temperature for feed conversion efficiency as the fish grow bigger.Temperature tolerance increases with size, but Atlantic salmon smolts are eurythermal (Able to tolerate a wide range of temperatures.) in the size range investigated.

Now as Willis would point out, clearly this is tank studies, and not the open ocean, and you can’t duplicate the complexity of the ocean in a tank. But the fish don’t seem to have a temperature issue, in fact they seem to thrive at warmer temperatures. The claim is that as oceans warm, less oxygen will be available, and that will stunt the growth of fish. This claim in the modeling paper comes from the elemental saturation curve for dissolved oxygen (DO) in water, which is much like that of CO2. From a lecture on water chemistry at keystone.edu:

I found this part of the lecture interesting, and was something I didn’t know:

Nota bene: 100% saturation does not mean that no more O2 can be held in solution. I have measured DO >200%. Does this mean that bubbles should be forming? No, not necessarily. Saturation here means that 10.92 mg/l can be held at equilibrium; if 200% is produced by intense photosynthetic activity, the extra amount will be lost (diffused) at the air/water interface.

a nomogram can be used to determine degree of saturation; use a straightedge to connect the water temperature and DO. Read the % saturation at the intersection of this line with the middle line.

Dissolved Oxygen % Saturation Nomogram

· at 10 meters, with a temperature of 10°C, at surface pressure would hold (at 100% saturation) 10.92 mg, but you may find 15 mg/l.; compared to the surface it would be supersaturated, but at the depth and pressure it’s at, it may be less than saturated.

o How can water be supersaturated?

§ intense photosynthesis

§ entrainment of air falling over a dam or spillway; high pressure of impact drives gases into solution; may lead to gas bubble disease, a problem in TVA dams

§ affects fish if subjected for a few hours to >115% saturation; bubbles form in tissues; emboli collect in gills causing anoxia and death; also affects cladocerans. Other biota, e.g., crayfish and stoneflies are hardier.

So, too much oxygen is also a problem. But what really piqued my interest wad the statement of “intense photosynthesis” as a cause. That made me wonder if photosynthetic algae and diatoms would respond to increased temperature, so I went looking and found this paper: Production and fate of extracellular polymeric substances produced by benthic diatoms and bacteria: A laboratory study by Lundkvist et al.

And the graph showing how photosynthetic oxygen production changes with temperature, again hard data from observation:

So, it seems to me that the ocean already has this worked out. If O2 can be supersaturated, and “intense photosynthesis” can be a cause, it would seem that warmer water that normally would get oxygen from air-sea interaction and entrainment might be supplemented from increased algal photosynthesis.

Besides, broad differences in oxygen content by latitude are well known:

Image: Wikipedia

And fish aren’t static entities…they move. So I suppose I’m not too worried about global warming shrinking fish. Overfishing is likely a far greater problem for reduced fish size, as are oxygen deprived dead zones due to fertilizer runoff as we’ve seen in the Gulf of Mexico:

Dead zones occur throughout the world and are caused primarily from excess fertilizer and animal manure run-off, as well as, emissions from sewage treatment plants, urban and suburban run-off, and air emissions from vehicles. The largest dead zone in the country occurs at the mouth of the Mississippi River in the Gulf of Mexico each spring. In past years, the dead zone (pictured in the satellite image as the red coastal areas around Texas, Louisiana, Mississippi, Alabama, and Florida) has encompassed some 5,000 square miles. – ewg.org

It made me wonder why the warm seas of today have any large fish in them. Somebody better tell the big fish, ‘the models say they can’t grow that big in warm water’. Then there are the epocs of the past when the seas and oceans were warmer. The large fish fossils of those times must be fake.

Did I see that dreaded term ‘computer modelling’ again?? They were then ‘surprised’ to see the fish shrinking (on the computer screen that is). Well that ‘proves’ it then, whatever the computer said must be true.

It’s very interesting. I might just pick up the book. It describes cronyism and conflicts of interest in the world of science funding and publication. Just thought it would be interesting to people here.

Personally, I think this is less likely due to too little oxygen and more likely due to the temperatures they kept the fish at along with their methodology. If you look, they kept the fish at the same temperatures all the time. Some fish don’t like to be at certain temperatures and 18 C is really at the upper limit of species tolerance here as evidenced by the highest mortality numbers and simple check of species preferred temperature; just because they can tolerate a temperature doesn’t mean they like it. One would think that these guys would likely seek cooler water if given the chance.

Something else to consider is that higher temperatures will do two things to your tank: 1.) It will reduce oxygen solubility. Given that they made sure that all tanks had at least 80% oxygen saturation in their outflows, this should not have been a concern. 2.) It will increase the metabolism of your inhabitants increasing the amount of biological waste they produce reducing your water quality. This does affect your tank life’s growth rates because less pristine/healthy water is less conducive to rapid growth. This would make your tank inhabitants smaller at higher temperatures. However, in the ocean, this would not be a problem because you do not have the closed environment issues that all tank environments suffer from.

Had they kept the higher temperature fish in a cleaner environement, they might have closed the growth deficit. This is why you raise aquarium fry in a bare bottom tank, feed them three times daily and vacuum that bottom once daily before doing a massive water change of at least 2/3 water volume to maximize your fry growth. It’s about as close as you can get to simulating a lake type environment in the home aquarium.

But that’s what my untutored hobbyist insticts tell me from looking at their methods. There are just some things they don’t say.

This story is from the State of Georgia, USA and the fish was caught in a slough off the Ocmulgee River in the south-central part of the State. It is a bit hard to believe that this water was either cool or oxygen rich. At least not on June 2nd – the date of the catch.

About other large bass and why they have not been certified as breaking the 1932 record:

Now ” Shoulda woulda coulda,” means I’m out of time
Coz “Shoulda woulda coulda”, can’t change your mind
And I wonder, wonder, wonder what I’m gonna do
“Shoulda woulda coulda” are the last words of a fool

Well of course. The people living in the Alps are also only half as tall as they should be because of the thinner air and less oxygen up there. Awesome, another climate prediction, the truth of which I can check within my life-time.

george e smith says:
Can’t think of a fish that is particularly big found in the Arctic ocean.

Do you count whales as a fish ? :-)…..”””””

WUWT is a science site; well no, it is actually THE science site, and Dr Judith Curry notwithstanding, I do consider myself to be a scientist. Actually my business cards, when I have had them, always said Engineer/Scientist.

And I can spell Botany, so even I know that whales are mammals, and not fish.

But it does terrify me to think how big whale sharks, and great whites would get, if they ever discovered how nice it is to live up in the arctic ocean; think of all the sea bears the GWs could eat; and all those Walrussters too.

Yet another painful-to-read “study” press release.
1. A finding is put forth.
2. It is derived from a model
3. The results are discussed as if they were data.
4. The authors express surprise that these findings might ‘exist’
5. The “data” is used to “predict” something, while the findings as declared as “important” for the understanding of how things “might” change with “a warming climate”

Are there any computer-savvy fellers out there that could write a model to model a climate change press release? Then we could be surprised every day! We could find importance in a myriad of suggested problems, from what Mr. Snofgrass had for supper or whether his Ice cream melts more quickly in August.

The cumbersentence below is a perfect example of word-count padding and precious little else.

“But the unexpectedly big effect that climate change could have on body size suggests that we may be missing a big piece of the puzzle of understanding climate change effects in the ocean.”

This story is from the State of Georgia, USA and the fish was caught in a slough off the Ocmulgee River in the south-central part of the State. It is a bit hard to believe that this water was either cool or oxygen rich. At least not on June 2nd – the date of the catch.

Well the only reason a larger record LMB hasn’t been caught, is that Ray Scott decreed that only registered paying members of B.A.S.S were aloud to be recognized as having caught a record Large Mouth Bass, and preferrably in the BASSMaster’s Classic; and furthermore, flyrod catches were not eligible to be recognized as catching a large LMB.

Other than that, California has plenty of large LMBs specially around San Diego.

“We were surprised to see such a large decrease in fish size”, in our computer. This saved us days or weeks of cold and wet work at sea actually looking at what was happening in reality, It also avoids the danger caused by us being unable to manipulate field observations as we would like to receive ongoing funding.

tried posting this on the climate news thread, but the comment failed to go thru. it’s more relevant here anyway:

1 Oct: The Conversation: Guy Pearse: What about your carbon pawprint?
(The Conversation is funded by CSIRO, Melbourne, Monash, RMIT, UTS, UWA, Canberra, CDU, Deakin, Flinders, Griffith, La Trobe, Murdoch, QUT, Swinburne, UniSA, UTAS, UWS and VU)
(Guy Pearse receives funding from UQ for his fellowship.)
The ecological consequences of pets are significant when you consider the land needed to produce the energy and resources required for a large dog are equivalent to that of a four-wheel drive Land Rover; a medium dog is equivalent­ to a VW Golf. Or so say Brenda and Robert Vale, authors of the provocatively titled Time to Eat the Dog. Among many reason­able observations they note that we face real problems “when everyone starts to have a big car, big house, big family and a big dog”…

Guy Pearse
A former political adviser, lobbyist and speechwriter, Guy grew up in Townsville and was educated at James Cook University (BA Hons), Harvard (MPP), and the ANU (PhD). He was a member of the Liberal Party for 19 years and worked for various Liberal politicians including former environment minister, Robert Hill. He has been government relations and policy adviser for numerous industries and environmental organisations, and a consultant to the Australian Greenhouse Office. While studying at the Kennedy School of Government and Harvard Business School in the mid 1990s, Pearse also worked on the advance staff of then US Vice President, Al Gore…
His thesis became the basis for the “Greenhouse Mafia” episode of ABC’s Four Corners in February 2006…

where i am the bigger fish are in warmer water.
When i go on fishing trips to the tropics the size of the fish is not tiny. what a load of crap this is embarrassing. If they have degrees they need stripping.

George, I do know whales are mammals.. just very big ones that live in the sea.

There are actually some biggish fish that live down south, I believe some of them even have anti-freeze in their circulatory systems. Whales carry their antifreeze under their skin.
You are right though, the really big fish do prefer warmer waters, although those big whaler sharks are partial to a bit of seal for breakfast, lunch and tea, so a venture into colder waters is often on the cards.

btw, I also can put BSc and BEng on my card, plus MEng and maybe soon, Piled high & Deeper!!

“Down And Dirty Science –
An Exploration of the Lengths some Scientists will go to for Credit, Fame, and Glory….. It describes cronyism and conflicts of interest in the world of science funding and publication. Just thought it would be interesting to people here.”

Haven’t we seen the study suggesting some corals have done just that (Pacific if I recall rightly)?

And they mention the tropics being the most impacted but I thought AGW meant most of the warming would be nearer the poles with the tropics being the least impacted? Or does it only affect the air temps?

[I got no time for references or checking right now I gotta rush – apologies].

I wonder if the same people who believe the small increase in ocean temperature will cause a significant decrease in dissolved oxygen (curiously, I have never noticed that fish in warmer waters are smaller than in cold waters, rather the opposite if anything, but hey, what do I know) also believe in ocean acidification due to the same warming oceans absorbing more CO2 from the atmosphere….

Hasn’t that books outlandish claim been debunked, like, years ago?
“Vale, Brenda; Vale, Robert (2009). Time to Eat the Dog?: The Real Guide to Sustainable Living.”
( http://en.wikipedia.org/wiki/Brenda_and_Robert_Vale )
2009? And that Australian superscientist brings it up 3 years later? Do you import books with a canoe?

After years of diligent research, I’ve concluded that (a) bass are very sparsely populated, (b) they rarely exceed one pound, (c) BASS tournament TV is computer animation and,(d) the size is dispersion must be caused by global warming. I’ve conducted this research every available weekend for years.

So sad to see climate “science” dragging down other fields of scientific study, in this case marine biology.

I think this little ditty explains it well. Oh, the marine biologist bone is connected to the biology bone, the biology bone is connected to the College of Liberal Arts and Sciences bone, the College of Liberal Arts and Sciences bone is connected to the research University bone, the research University bone is connected to the Federal scientific funding agency bone, the Federal scientific funding agency bone is connected to the Public Sector tax collector bone, the Public Sector tax collector bone is connected to your wallet.

catweazle666 says:
October 1, 2012 at 3:42 am
I wonder if the same people who believe the small increase in ocean temperature will cause a significant decrease in dissolved oxygen (curiously, I have never noticed that fish in warmer waters are smaller than in cold waters, rather the opposite if anything, but hey, what do I know) also believe in ocean acidification due to the same warming oceans absorbing more CO2 from the atmosphere….

[Emphasis mine]

Here is one of many great dichotomies between the believers and the skeptics. Are the oceans really becoming less alkaline (not more acidic) or are the oceans giving up stored CO2 as they warmed over the last few decades? Both cannot obviously be true.

Oceans tend to absorb CO2 as the cool, and give it up as they warming. Shouldn’t a warming ocean have less CO2 than a cooler ocean?

BTW: We also know there is no evidence to show that the oceans are currently warming.

I have a problem relating this finding to the observed size and population density of marine species around the outflow from power stations, or around the legs of the offshore platforms.
In other words, where the water is warmer it seems to support much more marine life and of larger size.
It therefore seems counter-intuitive to believe that warming oceans result in smaller fish. Perhaps it just means that population growth is such that there are more juvenilles. Perhaps there is a link to fishing…. certainly the fishing around the platforms is better than away from them, or so I have been lead to believe.

At any rate, if the data suggests something that is so completely counter-intuitive and, more importantly, counter to observed patterns elsewhere it suggests that either the data is incomplete or that the science is incomplete. Maybe it rests on an assumption that is wrong or on an accepted belief that on closer inspection will prove to be wrong. For example, the data may be that fish are getting smaller.
Is this mature fish or a proportion of all fish? Is the fish population increasing or decreasing? is it simply an abundance of juveniles?
Or maybe the assumption is that the oceans are warming. Are they warming?
The other aspect,as any of the fishing guides will tell you, is that fish are attracted to the warmer waters causing uneven and changing populations. Quite evidently, fish like warmer waters. Ergo, how can it be bad for them?
But I get it. You can’t publish any scientific report these days nor get good grant money unless you throw in the obligatory “Warming is Bad” message. It is getting so that to extract the science these days you not only have to read the report but also decode it to mine the real data and science from the revenue generating propaganda. If there is still any real science contained in the report that is.

Nemo is likely getting smaller, but because of overfishing, particularly of salmon. I might point out that also, the need for less fat in a warmer ocean, particularly salmon again, might also be a factor and finally, if the ocean warmed up a couple of degrees, the Atlantic salmon would just swim 100km or so further up Davis Strait if they didn;t like the warm water. Sheesh – I’m only a geologist, too.

As a matter of fact some of the best spots for catching specimen fish are around or immediately downstream of warm water outlets which raise the water temperature significantly. This is known by anglers all over the world who choose to fish near power station outlets etc.

Shame these ‘modellers’ didn’t bother to check with people who best know fish – the anglers – and get some real-world data rather than working from an unfounded hypothesis.which only serves to highlight their own ignorance.

Mind you I expect there were mega-bucks at stake so they wouldn’t dare disturb the results of their ‘modelling’ with Facts.

Just another waft of the stench of corruption that goes by the name of climate change.

There is another proposition more associated with Darwin than warmin’. It may be that fish are adjusting to the size of catch. Netting size means that the genetically challenged smaller fish are able to persist and mate and the larger species and their genes are eradicated. When one sees the aridity of the majority of our oceans it is s tough proposition to swallow that oxygen in water is under threat. We see the hand of the politicians in all of this; their failure to deliver legislature that preserves stocks is especially damning of the failure of the EU, the general, casual references to a convenient phenomenon that they call AGW is a let-out for all of their awfulness as the blame for anything that is too critical of them or, like the use of Alchemy to derive results beyond the level of current intellectual understanding. When you have organisations such as the BBC demanding that every production has an ethnic diversification content and respectful nods in the direction of AGW then their is little hope that light/fact will illuminate this topic.

Will the size of the Fukushima-Daiichi radioactive fish make any difference? All 15 Bluefin Tuna caught by a research vessel off San Diego were contaminated…and the controlled press ignored it.Orwell had the wrong year….

The alternative hypotheses – over fishing and dead areas – are the far more likely cause. Over fishing has certainly shrunk dramatically the size of fish, whether it be the dorado in the River Parana in southern Brazil, or mackerel around the British coastline.

Of course warmer water causes smaller fish. Don’t you remember Hemingway’s famous story of the Cuban fisherman: The old man and the Smelt. Who can forget the epic struggle between Santiago and the sardine?
/sarc

George, I do know whales are mammals.. just very big ones that live in the sea.

There are actually some biggish fish that live down south, I believe some of them even have anti-freeze in their circulatory systems. Whales carry their antifreeze under their skin.
You are right though, the really big fish do prefer warmer waters, although those big whaler sharks are partial to a bit of seal for breakfast, lunch and tea, so a venture into colder waters is often on the cards.

btw, I also can put BSc and BEng on my card, plus MEng and maybe soon, Piled high & Deeper!!…..”””””

Andy, if I was in your shoes, I certainly would do that. I can tell you that I never could have even started my Industrial career in the USA, as aPhysics/Maths graduate, if it had not been for my Radio-Physics, and associated Electronics instruction at UofA; but down through the years, I found that it was my fundamental Physics, that allowed my engineering common sense to know, that I was working in an environment of “you can’t get there from here” restrictions, that they tend to not teach in Engineering courses. Stops a lot of useless thrashing around in the wilderness, trying to solve an unsolvable problem, if you know the finite restraints.
I was working on an MSc almost through to the finish, including having my thesis work done, but due to this’n’that never finished and got the shingle. Got all the learning benefit; but make sure you get the wall art as well, since the Judith Currys of the world demand that there be paperwork behind you.
And my work today is mostly all beholding to a 1926 text book, that very few white folks, and no minorites at all, even know exists.
Good luck with the MEng.

“Note the press release headline: Fish getting smaller as the oceans warm: UBC research – they tout that as if it were measured, it isn’t”
that is so typical LSM – the legacy media is trumpeting any CAGW rant, incredibly often, without any check, taking models as reality.
The warmlist is trying to keep pace with it but…

I had heard that Greens complain of ‘thermal pollution’ from nuclear powerplants warming the rivers theircooling water comes from. I also read that it should more properly be called ‘thermal enrichment’ in view of the beneficial effects upon all life in the river, particularly in terms of increased fish size.
Does anyone have a link to these River-based measurements?

The researchers used computer modeling to study more than 600 species of fish from oceans around the world and found….exactly what their models were designed to show, and they were surprised. Confirmation bias at work, no actual evidence being presented.

I am getting tired of seeing my money wasted on propaganda masquerading as science, and even more so I am getting tired of idiots on the left coast.

[tiny bit of research on fish] Do the scientists know that almost all fish have Hemoglobin, except for some Arctic species? Hgb allows much more O2 to be carried to the tissues than O2 only dissolved. And the sigmoid characteristics of the human hgb “saturation curve” means that a large decrease in the pO2 which hgb is exposed to, first leads to a relatively small decrease in the O2 still carried and delivered. For example, in the case of humans a decrease in the normal pO2 the hgb is exposed to in the lungs from pO2 ~100 to 60 still leaves the hgb carrying 90% of its O2 out to the tissues, which is plenty to keep tissue function normal since only about 1/3 of the O2 carried by hgb out of the lungs is used by the tissues during normal activity. Then there’s also the question of whether fish increase their hgb concentration in the face of decreased ambient-gill level pO2 by increasing red blood cell production, which humans normally do at altitude.

Other adjustments by the fish are possible even if Oceanic O2 does decrease. Therefore, I have to trust the fish over the “scientists”.

Andy, although your comment is factually true, I think a strong scientific case for increased CO2 levels contributing to Catastrophic Anthropogenic Global Wiggly-butt Syndrome (CAGWS for short) can be made.

As empirical evidence shows, increased levels of CO2 have increased forest and crop yields due to improved photosynthesis efficiencies. With the increased supply of grains and vegetables, food and animal feed prices have fallen, allowing more disposable income available for food expenditures and caloric intake and, voila’, CAGWS.

If a graph was made showing increased CO2 levels compared to increased US obesity rates (aka CAGWS), I’m confident a very strong CO2/CAGWS correlation would be shown…

Well, rain brings lots of oxygen to the sea-water. More storm-water saved on land -> rainfall increases. 2] rain washes CO2 into the sea -> corals, algae collect the CO2,; keep the carbon for themselves and release the oxygen from the CO2 into the water; therefore, more CO2 is replenishing better the seawater with the essential oxygen

As long as the government’s / tax $$$ are given – they will discover all sorts of bad things, nothing good will happen… because of the phony GLOBAL warming… Well, lets help them with more bad news: in warmer climate the testicles start sagging down to your knees -> obstruct walking — when colder -> they disappear, to keep warm. 2] when colder, brings you in bed closer to your partner – when too hot, you even prefer another bed = more divorces, tragic, panic; give them extra taxpayer’s cash – so they can invent even bigger lies

And why do they think that fishing which takes out the biggest ones and leaves only the smaller ones to breed have nothing to do with the size change? Are climate scientists as ignorant and narrow minded as every thing we read from them seems to suggest or is it that mentioning climate change is the open sesame to fat financial handouts still?

We generally seem to find bigger fish of a given species in our catches in warmer seas than in colder and that seems to correlate with there being two or three factors – fewer predators (e.g., as sharks are increasingly being fished), warmer water, and more life in the food chain for those fish to eat in the warmer seas. There’s a lot of research on the subject, but it is constrained by our inability to run proper control experiments to prove whether the correlation shows a direct causal effect. So we don’t really know, even now.

However, there was some very solid research done in 2008, culminating in a paper in 2009. It involved a controlled experiment using freshwater fish – widemouth bass. It showed conclusively that these bass grow bigger in warmer water. We assumed that it could probably apply equally to seawater species – safe assumption, though we cannot prove this either way under a proper controlled experiment as I say. This was very important research because of its implications for freshwater fisheries management of conservation and stocking for all cash or food fish stocks and sporting fish stocks.

Here are the details of the research:
Andrew L. Rypel, Assistant Professor of Applied Fish Ecology at Virginia Tech.

Paper: Rypel, A.L. 2009. Climate-growth relationships for largemouth bass (Micropterus salmoides) across three southeastern USA states, Ecology of Freshwater Fish 18: 620-628.
The paper was produced during his post-doctoral experience at the USDA Forest Service and University of Mississippi (2008-2010).
Paper can be downloaded from: http://www.srs.fs.usda.gov/pubs/38881

Probably because of all that warmer water! (Assuming the widemouth bass study applies equally to seawater species.)
A bit of a bother that. The warmists go around insisting (without evidence) that fish will become smaller as temps rise.
Ruddy widemouth bass…